It is estimated that one in ten children in the U.S. is the brother or sister of a child with a chronic illness or developmental disorder (CI/DD). These children grow up in homes where there is a strong focus on health issues and provision of health care services, as well as individual (e.g., internalizing symptoms) and family factors (e.g., maternal distress) that have been linked with somatization in children. Yet little is understood about the rates and correlates of somatic symptoms in siblings of children with CI/DD or their health care utilization patterns. Excessive somatic complaints in children are associated with disruption of academic and social functioning, greater use of health care and mental health services, and risk for unnecessary, invasive medical diagnostic procedures and treatments. Identification of children who are at greater risk than the general population for developing a high degree of physical symptoms has important implications for pediatricians, mental health practioners, and health care planners. The primary aim of the present application is to develop an increased understanding of sibling adaptation to CI/DD, with a focus on physical symptoms and the ways in which exposure to CI/DD within the family and parental reinforcement of sick role behavior may interact in the development of somatic symptoms in children and adolescents. The principal investigator of this study is a new investigator. Using diabetes as a representative chronic illness and pervasive developmental disorder (PDD) as a representative developmental disorder, this study will examine somatic symptoms, psychological symptoms, and reinforcement of sick role behaviors, and the associations among these variables in siblings of children with CI/DD in comparison with siblings of healthy children. Participants will be 50 siblings (ages 8-12 years) of children with diabetes, 50 siblings of children with PDD, and 50 siblings of healthy children, and parents of these children who will be assessed using standardized questionnaires. Parent attributions about siblings' somatic symptoms and the extent to which parent and sibling reports of somatic and psychological symptoms agree will also be assessed in siblings of children with CI/DD and siblings of healthy children.